Refrigerating apparatus



May 15, 1956 J. W. .JACOBS REFRIGERATING APPARATUS 2 Sheets-Sheet lFiled Aug. 26, 195.3

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INVEN TOR. James W. Jacobs W' W LM/Jd/V His Attorney May 15, 1956 J. w..JACOBS 2,745,257

REFRIGERATING APPARATUS Filed Aug. 26, 1955 2 Sheets-Sheet 2 A* I @1 WRECIRCULATQD Ammy 1 C Algso'jl m FRESH AIR Abm-:D

78 INVENTOR.

James w Jacobs BY www His Attorney Fig. 5

United States Patent REFRIGERATING APPARATUS James W. Jacobs, Dayton,Ohio, assigner to General Motors Corporation, Detroit, Mich., acorporation of Delaware Application August 26, 1953, Serial No. 376,594

8 Claims. (Cl. 62-4) This invention relates to refrigerating apparatusand more particularly to an automobile air conditioning system and thecontrols therefor.

It is an object of this invention to provide an automobile airconditioning system in which a single knob is used for not only startingand stopping the air conditioning equipment but also for controlling anumber of items such as the air velocity, the air temperature and theintroduction of fresh air into the passenger compartment. Moreparticularly, it is an object of this invention to provide a simple andinexpensive air conditioning control device which may be mounted on thedashboard of a passenger automobile and which selectively actuates anumber of individual air conditioning controls by means of simplemanipulations of the knob.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Figure 1 is a plan viewV with parts broken away showing a passengerautomobile equipped with a preferred embodiment of the invention;

Figure 2 is a schematic wiring diagram showing the various electricalcontrols;

Figure 3 is a front elevational view showing the control knob and thecontrol panel;

Figure 4 is a plan View with parts broken away showing a preferredembodiment of the control; and

Figure 5 is a vertical sectional view taken at right angles to Figure 4.

Referring now to the drawings wherein a preferred embodiment of theinvention has been shown, reference numeral 10 designates a conventionalpassenger automobile having an engine compartment 12, a passengercompartment 14 and a luggage compartment 16. The air conditioningequipment which serves to cool the air for the passenger compartment 14includes an evaporator 20 which, for purposes of illustration, has beenshown located in the luggage compartment directlyI beneath the usualpackage shelf 22. The refrigeration liquefying system includes acompressor 24 which is adapted to be driven from the main car engine 26through a clutch 28.

A solenoid 30 having two parallel coil sections 110 and 112 (see Figs. land 2) serves to actuate the clutch 28. The clutch 28 is of the typeshown in my copending application Ser. No. 365,593 filed July 2, 1953,and

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A fan 40 which is directly driven by the main car engine serves toforcefully circulate air over the condenser and the engine radiator 34at all times when the engine operates. Air to be conditioned is suppliedto the air inlet side of the evaporator through a return air grill 42located in the package shelf of the car and fresh outside air issupplied to the air inlet side of the evaporator through a pair of freshair inlet ducts 44.

Fresh air inlet control dampers 46 are mounted in the ducts 44 so as toopen and close the air passage in the fresh air ducts. A solenoidoperator 48 is provided for controlling the fresh air dampers 46 throughsuitable linkage mechanism 50. The air dampers are of the normallyclosed type which only open when the solenoid is energized. A pair ofevaporator blower elements S2 have been provided for discharging theconditioned air into the passenger compartment of the car throughsuitable air distributing ducts 54 which, for purposes of illustration,have been shown as extending substantially the full length of thepassenger compartment on opposite sides of the same. The blowers 52 arethe variable speed type which are adapted to have their speed controlledin a manner to be explained more fully hereinafter.

The air conditioning apparatus is normally controlled by the' driver ofthe car and since the driver may Wish to change the setting of the airconditioning equipment while driving the car, it is important that thecontrols for the air conditioning equipment be not only readilyaccessible to the operator but that a minimum number of control knobsVor buttons be used. In the invention shown, the air conditioning controlcomprises a control assembly generally designated by the referencenumeral 60 which is adapted to be mounted on the dashboard 62 of thecar. The control comprises a single control knob 64 which is carried onthe end of a shaft 66 which in turn is rotatably supported on a lever68. Simple rotation of the knob 64 and the shaft 66 operates a rheostat69 which controls the speed of the blower motor or motors.

The lever 63 is mounted for pivotal movement in a vertical plane about ahorizontal axis 70 carried by a supporting element 72. A mercury switch74 mounted on the inner end of the lever 68 serves to control the freshair damper solenoid 48 and is so constructed and arranged that when thecontrol knob 64 is in its lowermost position (as shown in Figs. 3 and 5)the fresh air dampers are open so as to admit a maximum amount of freshair into the evaporator housing. The fresh air thus admitted is thendischarged into the passenger compartment either with or without beingcooled. By raising the knob 64, the lever 68 will pivot about itssupport 70 so as to tilt the mercury switch 74 and open the circuit tothe damper control solenoid 43 and thereby cause closing of the dampers46.

The support 72 is mounted for oscillation about a xed pivot pin 78whereby the control knob 64 and the lever 68 may be moved sideways aswell as up and down. The lever 68 carries a plurality of spring pressedslidable contactors 80, 82 and S4 which are adapted to slidably engagethe resistance wire 9i), contact bar 92 and contact bar 94,respectively. The elements 9G, 92 and 94 are carried by the insulatingelement 96 which in turn is carried by the stationary supporting bracket100. The bracket 101) is secured to the escutcheon plate 102 which inturn is secured to the instrument panel 62.

As shown in the drawings, when the knob 64 is moved to the far left orthe off position, all of the air conditioning equipment is inoperative.As the control knob is moved from its olf position to the positiondesignated Ventilating position, the contactor 84 moves into engagementwith the contact bar 94 (as shown in Fig. 4) so as to close the circuitto the evaporator blower motors and thereby cause these blower motors tocirculate air Vspeed may be controlled b y rotating the `knob 64.VAsfthe knobeis moved from its'ventilatingposition to that positiondesignated as on position, the contactor 82 moveslinto engagement withthe 4contactsbar 92 so as to Y close the circuit to the main controlthermostat 104 which for purposes of illustrationhas been shown mountedin the return air-passage so as to respond tothe temperature of the airin the passenger compartment of the car.

The thermostatltm controls a solenoid `vN6 which'op-V crates a switch'-108 arranged in series lwith the clutch operating solenoid coilsections 110 and 112as shownrin Figure 2. Whenever the airconditioningcontrol knob is inthe fon position and theth'ermostat l 104indicatesthat cooling is required, -theswitch 108 will be held closed.When'the switch 103 rst -closes,the solenoid coils il@ andi-l2 arebothenergizedand serve to operate the clutch 2S andcause the -compressorto be operated bythe main carengine 26. Once the clutch is moved intoengagement, the switch liiis opened so -as-to deenergize the coilsection B2 and thereby reduce the amountV of current required by theclutch operating solenoid. The coil section 111B is strong enough tomaintain the clutch in the engaged position once it is fully engaged sothat the clutch will remain-engaged until either the thermostatlM-opensthe circuit yto the solenoid lit orthe manually operated contactor`82 ismoved out of engagement with the contact resistance is in circuit withthe heater'll when Athe con.-

trol knob rst moves into that. position in vwhich the contact 80 engagestheresista'nce element 9). As thezcontrol knob Vmovesfurther to theright, more resistance will be cut out, consequently, more heat will beadded to the thermostat with the result that the'further to the rightVone moves the control knob 64,\the more-cooling Awill take place.

T here may be times when either the head pressure or the suctionpressure in the refrigeratingsystem becomes abnormally high orlow,lrespectively, in which case'the refrigerating equipment shouldbeturned off so as to preventV damage to the compressor and-so as toprevent ineficient operation of the airconditioning system. For thispurpose a high pressure cut-outdevice 11S and a lo'w pressure cut-outdevice have been provided as shown l. In a single operativerefrigerating system, a compres-k sor, acondenser, an evaporator,refrigerant tiow connections between said compressor, condenser'andevaporator, aprirne mover for said compressor, a 'clutch between saidcompressor and said prime mover,l a control for said clutch, blowermeans for circulating'air to be conditioned in thermal exchangerelationship with said evaporator, a control for-said blower means,ductmeans-for conveying ffeshf-a'ir intoth'ermal exchange 'i-latenship`'with siteY evaporator, a fresh air damper in said duct means, acontrol for said fresh air damper, and a common actuator for saidcontrols, said controls comprising a iirst lever,

means for pivotally supportingsaid rst lever for oscillation about agiven axis for exercising one of said controls, a second lever pivotallysuported on said rst leverfor oscillation about a different axis forexercising another of said controls, and means 'including a control knobrotatably supported by said second lever for exercising still anothercontrol.

2. In a single operative refrigerating ysystem, va com-.

pressor, a condenser, an evaporator, refrigerantow connections betweensaid compressor, condenser and evaporator, a prime mover for saidcompressor, a clutch between said compressor andsaid prime mover, acontrol for said clutch, blower means for circulating air to-beconditioned in thermal exchange relationship with said evaporator, acontrol for varying the quantity-of air circulated byfsaid blowermeans,land a common actuator for said controls, said controls comprising Vaiirst lever, means for supporting said first lever'for oscillation abouta given axis, a second lever pivotally lsupported on :said iirst leverforoscillation relative to said first leverfand meansrincluding a mastercontrol knob supported. fory rotational -movement y'relative to `saidsecond lever, :said

control for said clutch Vcomprising means voperated in response topivotal movement of said rst lever, said control for said'blower meanscomprising'a'rheostat oper-A ated in-responseto rotation ofsaid'master-controlzkndb. 3. Ina singlefoperative refrigeratingsystemioruse 1n a1r conditioning the passenger compartmentOanfautomobile, a compressor, a condenser, an -evaporator,lre-

Ymeans, duct means for conveyingfresh air into 'thermal exchangerelationship with said evaporator, a `fresl'r'air damper in said ductmeans, a control for saidfresh'air damper, andra common actuator'forsaid controls, said actuator comprising a rotatable lshaft arranged toVoperate Vsaidfblower control means in responseV to rotation of -suchshaft, a support for said rotatable'shaf'means for pivotally mountingsaid support, -pivotal movement of said support serving to operate saiddamper control means, means for pivotally supporting said'shaft-"support, pivotal movement of said last named means serving tocontrol 'said clutch control means.Y

v4. Ina single operativerefrigerating system, a compressor, a condenser,an evaporaton'r'efrigerant flowcouncctions between vSaid compressor,condenser andevaporator, a prime mover, power transmitting means betweenvsaid prime mover and said compressor including a clutch, blower meansfor circulating air to bek conditioned in thermalexchange relationshipwith said evaporator, duct means for conveying 'fresh air `into thermalvexchange relationship with said evaporator, a fresh air damper'in vsaidduct means, a Vmaster control element, meansresponsive to rotation ofsaid control'ele'nient for varying'tlie speed of -said blower means,means responsive to'oscilla- 5. -In a single operativerefrigeratingfsystem, acomptes- -sor, acondenser, an evaporator,refrigerant tion/connections between said compressor, condenser andevaporator,

aprirne mover, power transmittingmeans betweensaid prime mover and'saidcompressorincluding 'a clutch, blower means for circulating-.airto'be'conditioned -in thermal exchange relationship with said evaporator,duct means for conveying fresh air into thermal exchange relationshipwith said evaporator, a fresh air damper in said duct means, a mastercontrol element, means responsive to rotation of said control elementfor Varying the speed of said blower means, means responsive tooscillation of said control element in one plane for controlling saidfresh air damper, and means responsive to oscillation of said controlelement in another plane for controlling the operation of said clutch,said clutch control means including a thermostat operable in at leastone position of said master control element to respond to therefrigeration requirements for automatically operating said clutch.

6. In a single operative refrigerating system, a compressor, acondenser, an evaporator, refrigerant flow connections between saidcompressor, condenser and evaporator, a prime mover, power transmittingmeans between said prime mover and said compressor including a clutch,blower means for circulating air to be conditioned in thermal exchangerelationship with said evaporator, duct means for conveying fresh airinto thermal exchange relationship with said evaporator, a fresh airdamper in said duct means, a master control element, means responsive torotation of said control element for varying the speed of said blowermeans, means responsive to oscillation of said control element in oneplane for controlling said fresh air damper, and means responsive tooscillation of said control element in another plane for controlling theoperation of said clutch, said clutch control means including athermostat operable in at least one position of said master controlelement to respond to the refrigeration requirements for automaticallyoperating said clutch, and means for adjusting the temperature at whichsaid thermostat responds.

7-. In a single operative refrigerating system, a compressor, acondenser, an evaporator, refrigerant ow connections between saidcompressor, condenser and evaporator, a prime mover, power transmittingmeans between said prime mover and said compressor including a clutch,blower means for circulating air to be conditioned in thermal exchangerelationship with said evaporator, duct means for conveying fresh airinto thermal exchange relationship with said evaporator, a fresh airdamper in said duct means, a master control element, means responsive torotation of said control element for varying the speed of said blowermeans, means responsive to oscillation of said control element in oneplane for controlling said fresh air damper, and means responsive tooscillation of said control element in another plane for controlling theoperation of said clutch, said clutch control means including athermostat operable .in at least one position of said master controlelement to respond to the refrigeration requirements for automaticallyoperating said clutch, and means for adjusting the temperature at whichsaid thermostat responds, said last named means being adjusted bymovement of said master control element.

8. ln a single operative refrigerating system, a compressor, acondenser, an evaporator, refrigerant ow connections between sai-dcompressor, condenser and evaporator, a prime mover, power transmittingmeans between said prime mover and said compressor including a clutch,blower means for circulating air to be conditioned in thermal exchangerelationship with said evaporator, duct means for conveying fresh airinto thermal exchange relationship with said evaporator, a fresh airdamper in said duct means, a master control element, means responsive torotation of said master control element for varying the speed of saidblower means, means responsive to oscillation of said master controlelement .in one plane for controlling said fresh air damper, meansresponsive to oscillation of said master control element in anotherplane for controlling the operation of said clutch, said clutch controlmeans including a thermostat arranged to respond to the refrigerationrequirements for automatically operating said clutch, and meansresponsive to movement of said control means for Varying the temperatureat which said temperature responsive means operate said clutch.

References Cited in the file of this patent UNITED STATES PATENTS1,872,380 Woods Aug. 16, 1932 2,032,572 Hammers Mar. 3, 1936 2,187,397Goggins Ian. 16, 1940 2,264,821 Zukoski Dec. 2, 1941 2,346,017 ErrathApr. 4, 1944 2,361,855 McCormack Oct. 31, 1944 2,495,350 Smith Ian. 24,1950 2,569,009 Kuempel Sept. 25, 1951 2,636,356 Ryan Apr. 28, 19532,656,685 Borgerd Oct. 27, 1953

